Involved with EC 6.3.2.4 (D-alanine---D-alanine ligase), EC 6.3.2.7 (UDP-N-acetylmuramoyl-L-alanyl-D-glutamate---L-lysine ligase) or EC 6.3.2.13 (UDP-N-acetylmuramoyl-L-alanyl-D-glutamate---2,6-diaminopimelate ligase), EC 6.3.2.8 (UDP-N-acetylmuramate---L-alanine ligase) and EC 6.3.2.9 (UDP-N-acetylmuramoyl-L-alanine---D-glutamate ligase) in the synthesis of a cell-wall peptide (click here) for diagram. This enzyme also catalyses the reaction when the C-terminal residue of the tripeptide is meso-2,4-diaminoheptanedioate (acylated at its L-centre), linking the D-Ala-D-Ala to the carboxy group of the L-centre. This activity was previously attributed to EC 6.3.2.15, which has since been deleted.

modest activity against lipopolysaccharide-defective Escherichia coli and wild-type Escherichia coli rendered permeable with polymyxin B nonapeptide. Treatment of lipopolysaccharide-defective Escherichia coli cells with >2fold minimal inhibitory concentrations of DQ1 results in a 75-fold-greater accumulation of the MurF substrate compared to the control, a 70% decline in the amount of the MurF product, and eventual cell lysis, consistent with the inhibition of MurF within bacteria

site-directed mutagenesis, exchange of highly conserved lysine residue leads to highly reduced activity, activity can be rescued best by addition of propionate or other short-chain carboxylic acids, but only in a small extent by amines